Computer simulation of the structural and physical properties of silicate crystals and melts at high temperatures and high pressures
| Project/Area Number |
16540442
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Petrology/Mineralogy/Science of ore deposit
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| Research Institution | University of Hyogo |
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Principal Investigator |
MATSUI Masanori Univ. of Hyogo, Graduate School of Life Science, Professor, 大学院生命理学研究科, 教授 (90125097)
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| Co-Investigator(Kenkyū-buntansha) |
HAGIYA Kenji Univ. of Hyogo, Graduate School of Life Science, Research Associate, 大学院生命理学研究科, 助手 (70237907)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | silicate crystals / silicate melts / high temperature / high pressure / computer simulation / Earth' s mantle / breathing shell model |
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| Research Abstract |
Crystals and melts in the Na_2O-CaO-MgO-Al_2O_3-SiO_2 (NCMAS) system are important components of the earth's crust and mantle. Both molecular dynamics (MD) and lattice dynamics (LD) methods are used to calculate the properties of crystals, while the MD technique is applied to simulate melts. The interionic potential is taken to be the sum of pairwise additive Coulomb, van der Waals attraction, and repulsive interactions. In addition, in order to take account of many-body forces in crystals and melts, the breathing shell model is developed for simulation, in which the repulsive radii of 0 ions are allowed to deform isotropically under the effects of other ions in the system concerned. The net charges of the ions are constrained to be 2q(Na)=q(Ca)=q(Mg)=2/3q(A1)=1/2q(Si)=-q(0) to apply the potential to both crystals and melts with any composition in the NCMAS system. Required energy parameters, including the oxygen charge, repulsive radii, van der Waals coefficients of ions, and the oxygen breathing parameters, were derived empirically to reproduce the observed temperature-pressure-volume (T-P-V) equations of state of a wide structural. variety of crystals in the NCMAS system, as well as the measured volumes of enstatite, wollastonite, diopside, albite, and anorthite melts at high temperatures. In spite of a wide variety of crystals and melts studied, the LD and MD simulations are quite successful in reproducing accurately the measured structural and physical properties of both crystals and melts in the NCMAS system.
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Report
(4 results)
Research Products
(18 results)
